Metal halide and other high intensity discharge (HID) lamps have found widespread acceptance for lighting large area indoor and outdoor spaces. In the manufacture of HID lamps, it is often desirable to provide a controlled atmosphere for many of the components of the lamp to prevent premature failure of the components and thereby prolong the operating life of the lamp. For example, the exposure of the arc tube of an HID lamp to small amounts of oxygen during lamp operation will significantly degrade the components leading to lamp failure, thus shortening the operating life of the lamp. Further by way of example, the exposure of the arc tube to hydrogen may lead to diffusion of hydrogen into the arc tube leading to high starting and re-ignition voltages, and ultimately reduced life expectancy of the lamp. To prevent the exposure of such components to damaging atmospheres, it is well known to provide a controlled atmosphere for the components by enveloping the components in a desired atmosphere contained within an outer lamp jacket. Typically, the outer jacket of an HID lamp is filled with an inert gas such as nitrogen.
In view of the deleterious effects of the presence of impurities, it is desirable to nondestructively analyze the composition and impurity content of the gaseous atmosphere contained within the lamp outer jackets. Gas analysis by emission spectroscopy is well known in analyzing the composition and impurity content of gaseous atmospheres at low pressures (<about 0.1 atm). However, the gaseous atmosphere contained within an outer jacket of an HID lamp is typically at relatively high pressure (about 0.1–2.0 atm). There remains a need for nondestructive gas analysis by emission spectroscopy in high pressure gaseous atmospheres.
Accordingly, it is an object of the present invention to obviate the deficiencies of the prior art and to provide a novel system and method for nondestructive high pressure gas analysis.
It is another object of the present invention to provide a novel system and method for generating a discharge in a high pressure gas.
It is a further object of the present invention to provide a novel system and method for creating a stable electrical discharge in a high pressure gas contained in a sealed enclosure, so that the composition and impurity content of the gas can be spectroscopically analyzed without destroying the enclosure.
It is yet another object of the present invention to provide a novel system and method for emission spectroscopy of gaseous atmospheres.
It is yet another object of the present invention to provide a novel system and method for nondestructive analysis of HID lamps.
These and many other objects and advantages of the present invention will be readily apparent to one skilled in the art to which the invention pertains from a perusal of the claims, the appended drawings, and the following detailed description of the preferred embodiments.